Abstract : We have identified an important class of intermodal network design problems where we can prove that the submodular property holds. This class includes the intermodal channel selection problem as well as the terminal selection problem for one directional flow. We have just completed computation testing on multi-facility location problems to compare this methodology with commercial integer programming codes and are preparing this work for publication. This work was presented as a 'focus paper' at TRISTAN II in Capri, Italy in June 1994. The algorithm has been embedded as a tool in the CAPS Logistics Toolkit and is used by a number of commercial companies to locate facilities.